Vinyl chloride resin composition



United States Patent 3,520,953 VINYL CHLORIDE RESIN COMPOSITION KatsumiSugimoto, Tokyo, and Shiro Tanaka and Hiroya Fujita, Yokohama-shit,Japan, assignors to The Japanese Geon Co., Ltd., Tokyo, Japan NoDrawing. Filed Aug. 11, 1967, Ser. No. 659,858 Claims priority,application Japan, Aug. 11, 1966,

41/ 52,309 Int. Cl. C081? 29/24 U.S. Cl. 260-4390 2 Claims ABSTRACT OFTHE DISCLOSURE hancing agent selected from the group consisting of butavdiene-containing polymers, chlorinated polyethylene and clorosulfonatedpolyethylene.

This invention relates to a vinyl chloride resin composition havingexcellent heat distortion properties and, more particularly, it isconcerned with a colorless, transparent rigid vinyl chloride resincomposition having excellent heat distortion and good shock resistingproperties and excellent processability.

BACKGROUND OF THE INVENTION Vinyl chloride resins have now come intowidespread use in a large variety of applications as rigid syntheticresinous molding materials because of their character istics in thatthey provide colorless, transparent shaped articles and have anexcellent chemical resistance and a low gas permeability. However, thereare a fairly large variety of applications in which the material maynot'con veniently be used in spite of its desirable characteristics asset forth above because of its disadvantages, namely, a relatively lowheat distortion temperature, a poor processability and an 'insuflicientimpact strength. For'instance, the material may not suitably be used asa material for making industrial reservoir tanks and pipings in whichthe material is required to have a high heat distortion propertytogether with chemical resistance and in applications as a material formaking containers and bottles'for foodstuffs in which the material isrequired to be not only air impermeable as to prevent the contents fromrotting but also thermally resistant as to withstand pasturization andhot pack at high temperatures. Hitherto, there have been many proposalswith respect to elimination of such disadvantages of the vinyl chlorideresin. For instance, as vinyl chloride resin materials having improvedthermal resisting properties, there has been proposed (1) chlorinatedvinyl chloride resins, (2) vinyl chloride polymerizates prepared in alow tempera ture polymerization process and (3) blends of vinyl chlorideresin and poly-a-rnethylstyrene having an improved processability (4)blends of vinyl'chloride resin with a styrene-acrylonitrile copolymer,(5) blends with a styrene-methyl methacrylate copolymer and (6) blendswith a methyl methacrylate-alkyl acrylate copolymer, and as those havingan enhanced impact strength (7) blends of vinyl chloride resin with abutadiene-containing polymer, (8) blends with a chlorinated polyethyleneand (9) blends with a chlorosulfonated polyethylene. It also has beenproposed for eliminating the above three disadvantages at the same timeto incorporate (10) a s yrene- 3,520,953 Patented July 21 1970acrylonitrile copolymer and a chlorosulfonated polyethylene in vinylchloride resin as disclosed in Japanese patent publication No. 8,674/1965, and to incorporate (11) a styrene-acrylonitrile-butadieneterpolymer in a chlorinated polyvinyl chloride as disclosed in Japanesepatent publication No. 590/66. However, the improvements brought aboutin the prior art are insufficient and suffer from the defect ofsacrificing the desirable properties of vinyl chloride resin especiallycolorlessness and transparency. Namely, in case of (10), the improvementin thermal resistance is not entirely suflicient and the resultingcomposition has a poor transparency. In case of (11), the resultingcomposition has a sufficiently improved thermal resistance but anunsatisfactory processability owing to a poor processability of thechlorinated polyvinyl chloride and it is impossible to obtain colorlessand transparent product based on the chlorinated polyvinyl chloride.

It is an object of the present invention to provide a rigid vinylchloride resin composition which has excellent heat distortion propertyand good processing properties. Another object is to provide a rigidvinyl chloride resin composition having excellent heat distortionproperties, good processing properties and high impact resistance. Theabove and other objects will be apparent from the following description.

BRIEF DESCRIPTION OF THE INVENTION We have made many investigations forthe purpose of overcoming those shortcomings inherent in such prior artsand have discovered that a composition consisting of (A) 100 parts byweight of a mixture of (1) from 90% to 50% by weight of a vinyl chlorideresin and (2) from 10% to 50% by weight of astyrene-acrylonitrile-methyl methacrylate-a-methylsyrene interpolymerwith (B) from 0 to 30 parts by weight of an impact strength enhancingagent is colorless and transparent, excellent in thermal resisting andshock resisting properties, processable or fabricable without anydifiiculty in, e.g., injection molding, extrusion molding or vacuumforming processes, and especially excellent in thermal resistingproperty and fully serves the purposes of the present invention.

DETAILED DESCRIPTION OF THE INVENTION The vinyl chloride resin used inthe present invention may be polyvinyl chloride itself or a copolymer ofat least 80% by weight of vinyl chloride with at least one othercopolymerizable monomer.

The.styrene-acrylonitrile-methyl methacrylate-a-methylstyreneinterpolymer used in the present invention may be a copolymer consistingof from 5 to 40% by weight of styrene, from 5 to 20% by weight ofacrylonitrile from i 30% to 80% by Weight of methyl methacrylate andfrom 10% to 45 by weight of u-methylstyrene and, optionally, up to 20%by weight of other copolymerizable monoolefinic compound. Theinterpolymer is obtained by merely copolymerizing the monomer mixture.The other copolymerizable mono-olefinic compound includes: vinyl halidessuch as vinyl chloride, vinyl bromide and vinulidene chloride; vinylesters such as vinyl acetate and vinyl benzoate; acrylic andot-alkylacrylic acids and alkyl esters thereof such as ethylacrylate,butylacrylate and ethyl methacrylate; acryloand methacrylonitriles suchto by weight of acrylonitrile, from 40 to 60% by weight of methylmethacrylate and from 15 to 30% by weight of u-methylstyrene. The heatdistortion temperature of the interpolymer rises but the processabilityand compatibility to vinyl chloride resin decreases with increasing theamount of ot-methylstyrene contained in the interpolymer, so thatot-methylstyrene is used in the amount of at most 45% by weight. On theother hand, when the amount is less than 10% by weight, the resultingvinyl chloride resin composition has a low heat distortion temperature.

The styrene in the interpolymer has a significant infiuence on theprocessability of the interpolymer and an interpolymer consisting onlyof acrylonitrile, methyl methacrylate and a-methylstyrene has a verypoor processability and, when incorporated in vinyl chloride resin, willafford a composition of a poor processability and, in addition, noimprovement in thermal resisting and shock resisting properties will beobtained because of its poor compatibility to vinyl chloride resin. Incontrast, an interpolymer containing styrene exhibits a marvelouslyenhanced processability even if the styrene content is as low as 5% byweight. If the styrene content is more than 40% by Weight theinterpolymer is difiicult to use because of incompatibility with vinylchloride resin. In cases where the interpolymer is not sufficientlycompatible with vinyl chloride resin, the interpolymer will not be mixedintimately with the vinyl chloride resin as in the cases of aninterpolymer having a poor processability, so that the resultingcomposition exhibits poor thermal resistance, impact strength, tensilestrength and transparency. Interpolymers free of such defects may beobtained by copolymerizing a monomer mixture so that it contains from 5to by weight of acrylonitrile and from to 80% by weight of methylmethacrylate. The amount of acrylonitrile should be at most 20% byweight since the interpolymer containing more than 20% by weight ofacrylonitrile will usually give a strongly yellow color. Also, thecompatibility of the interpolymer to vinyl chloride resin should besupplemented by use of methyl methacrylate. The interpolymer notcontaining acrylonitrile does not have sufficient compatibility withvinyl chloride resin. Accordingly, its composition with the resinpossesses poor tensile properties, transparency, chemical resistance andheat distortion properties.

The vinyl chloride resin composition of the present invention containsas essential components a vinyl chloride resin and interpolymer asmentioned above. However, it is usually incorporated with an impactstrength enhancing agent since, in cases of a vinyl chloride resincomposition in which a thermal resisting property or a transparency isrequired, a shock resisting property is also required in a large varietyof applications. We have examined various compounds as impact strengthenhancing agent and discovered that butadiene-containing copolymers,chlorinated polyethylene and chlorosulfonated polyethylene enhance theimpact strength without substantially sacrificing the transparency andthermal resisting properties.

The butadiene-containing polymer includes polymers having a goodcompatibility with vinyl chloride resin and derived from butadiene andat least one member of the group consisting of styrene, acrylonitrileand methyl methacrylate. Preferred are the graft copolymers obtainableby polymerizing at least one monomer selected from the group consistingof styrene, acrylonitrile and methyl methacrylate in the presence of ahomopolymer of butadiene or copolymer of butadiene with another monomer.The desirable graft copolymers contain at least by Weight of thebutadiene homopolymer or copolymer. These polymers are commerciallyavailable under the trade names of Cycolac, Blendex, Kaneace, Kralastic,Hiblen and others. Chlorinated polyethylenes known in market arePlascon, Daiso-CPE, Blaslen and others. Among the chlorosulfonatedpolyethylenes commercially available is Hypalon. The preferablechlorinated or chlorosulfonated polyethylene contains from 20 to 35% byweight of chlorine. Y

The reason why the proportion of the interpolymer in the mixture islimited from 10% to 50% by weight is that, when the interpolymer is usedin an amount of less than 10% by weight it affords only a slightimprovement in thermal resisting property and when used in an amount ofmore than 50% by weight the desirable properties of the vinyl chlorideresin, especially chemical resistance, are adversely affected to a greatextent. The reason that the amount of the impact strength enhancingagent is limited at most 30% by weight is that when it is used in theamount exceeding the upper limit the resulting composition has poorstrength, hardness, creep resisting properties and chemical resistanceto be used practically.

The composition of the present invention thus obtained has thecharacteristics as follows:

(1) It has an excellent thermal resisting property.

That is to say, it is easy according to the inventionto obtain acomposition having a heat distortion temperature above C. which isimpossible in the prior art methods. Moreover, the composition isexcellent in creep resisting properties at high temperatures. The creepproperty is from 2 to 6 times that of unmodified vinyl chloride resin.The heat distortion temperature of the composition is nearly thearithmetical mean of those of the vinyl chloride and the interpolymer inproportion to their contents. In contrast, the vinyl chloride resincompositions with such as a styrene-acrylonitrile copolymer, astyrene-methyl methacrylate copolymer or ABS resin in prior arts havelower heat distortion temperature than that of their arithmetical mean.

(2) It has an excellent processability.

That is to say, it has a good processability such that is unexpectablein the conventional vinyl chloride resins. It can be easilyprofile-extrusion molded and injection molded and, in addition, has avery good vacuum forming property which makes it possible to deep drawin vacuum forming processes into shaped articles having uniform wallthickness and good dimensional stability, differing from theconventional vinyl chloride resins. Furthermore, it can be fabricated byblow molding, calendering, pressing and other known fabricatingprocesses more easily than the conventional vinyl chloride resins.

(3) It has an excellent impact strength.

Even if the composition which consists of the vinyl chloride resin andthe interpolymer and does not contain any impact strength enhancingagent, it can be conveniently applied in the manufacture of, e.g.,containers for foodstuffs where it is unnecessary that the material havehigher impact strength than the conventional vinyl chloride resins,since it is comparable with or superior to the latter in impactstrength. Moreover, a composition having a high impact strength as highas 10 times that of the conventional vinyl chloride resin can beobtained by incorporating in 100 parts by weight of a mixture (A) of thevinyl chloride resin (1) and the interpolymer (2) up to 30 parts byweight of the impact enhancing agent (B), which is applicable in themanufacture of, e.g., automobile appliances or parts where a high impactstrength also is required.

(4) It is colorless and transparent and has a good surface lustre.

This is an important feature of the present invention which isunattainable by the prior proposals. The shaped articles made out of thecomposition of the present invention are colorless and transparent and,in addition, superior in surface smoothness and lustre to those made outof unmodified vinyl chloride resins.

The composition of the present invention, of course, retains thedesirable properties of the vinyl chloride resins with thecharacteristics as mentioned above.

As illustrated above, the present invention which would bring aboutgreat improvements or advantages impossible according to the prior artand overcome the disand the resulting interpolymers were indicated asinteradvantages in the prior art is accomplished as a result polymersample A, B, C M, respectively. of detailed investigations on thecomonomer component TABLE 1 of the interpolymer and 1s charactenzed bythe subtle S 1 t1 amp ewi llll the scope choice of the comonomercomponent of the mterpoly ofthisinvemion Controls mer.

' Although the composition of the present invention can A B C D E F G HI J K L M be widely used in making electric appliances, automobileMethyl methappliances, pipes, containers for foodstuffs and for medi- 653g is 2 g3 28 g g g 8 22 g g cal supplies, household necessities andmany other arti- Acrylonitri 1g 1g 20 5 5 20 20 20 20 0 cles wherethermal resistance is required, it is of great 10 1 2 10 10 10 5 5O 3010 20 utility especially. in making containers and bottles for p Afoodstuffs and medical supplies requiring pasteurization 100 parts of amixture of 30% by weight of the interand/or hot packing since thecomposition does not depolymer thus obtained and by weight of a vinylform even at a fairly high temperature and has very exchloride resin(Polyvinyl chloride of a polymerization decellent vacuum forming or blowmolding properties and 15 gree of 1450, sold by the Japanese Geon Co.under the colorlessness, transparency and good surface lustre. In tradename of Geon-101EP) was added with 20 parts of applications such asbattery cases and the like, electric an impact strength enhancing agent(and ABS resin, sold appliances and automobile appliances where thermalreby the Japanese Geon Co. under the trade name of Hibsistance and shockresistance are required, there is conlen B-202), 2 parts of an organotinmaleate stabilizer veniently used a composition containing the impacten- (sold under the trade name of Stan BM) and 0.5 part of hancingagent. Also in this case, the colorlessness and calcium stearate andkneaded on a roll at 160 C. for 10 transparency and the good surfacelustre increase the minutes. The resulting sheet Was hot pressed at 165C. commercial value of the shaped articles made out thereof. and thencut into various sizes and subjected to test of The composition of thepresent invention is easily ob 2,, physical properites. The resultsobtained are given in the tainable by uniformly mixing the components bymeans 0 following Table 2.

TABLE 2 Jharpy Tensile Heat Creep (percent) impact strength Durometerdistortion strength at 20 C. hardness temp. 60C. C. Process- (Kg.-em./Trans- (Kg./sq. Dat; stock Interpolymer sample C.) aweek aday abilitysq.cm.) parency Color mm.) 20 C. 96 97 154 Excellent" 19.5 Excellent-Colorless 6.2 83 102 64 122' o 21. .-.do do.... 6.0 83 10s 53 101 18.8-.-do ..do 6.0 83 112 26 86 16.5 Good Slightly yellow. 61 83 95 148 18.9Excellent do 6.0 32 96 163 23.8 6.2 '84 97 82 152 19.8 6.1 3

77 153 200 183 Excellent. Light yellow. 6.1 34 82 121 200 5.6 Po0r Milky4.3 4 79 142 200 7.1 Good. Slightly yellow 5.2 83 76 159 200 4.2 PoorMilky 4. 35 78- 146 200 5. .do do.. 5.0 34 103 82 185 Excellent 20.5Excellent Yellow 6.2 3 76 168 200 Fair 3.4 do Colorless 5.9 32

No'rE.Testmethods were as follows: Heat distortion temperature=J ISK6745; Impact strength=JIS K6745; Tensile strength=JIS K6741; HardnessASTM D-785; Creep=Elongation (percent) under a tension of 2 kg./sq. mm.

of, e.g., mixing rolls, Banbury mixers or extruders. Also it may beprepared in any suitable manner. For instance, the components may beseparately dissolved in solvents and the resulting solutions may beadmixed. It also is possible to obtain a composition by polymerizing themonomer mixture yielding the interpolymer in the presence of the impactenhancing agent and mixing the resulting polymerizate with the vinylchloride resin.

The present invention will be now illustrated in more detail by thefollowing examples. Parts and percent are by weight unless otherwisestated.

Example 1 Into a polymerization vessel there were charged 300 parts ofwater, 3 parts of sodium dodecylbenzenesulfonate, 0.3 part of potassiumpersulfate, 0.2 part of tertiary dodecylmercaptan and parts of a monomermixture of the formulation as listed in the following Table 1, the freespace of which is then purged with nitrogen. The contents were thenmaintained at 50 C. with stirring and, after complete reaction of themonomers, the resulting latex was discharged from the vessel. The latexwas then coagulated by addition of a calcium chloride solution and thecoagulate was washed and dried to recover an interpolymer in finelydivided form. Themono While the stocks of the present invention (from1-1 to l7) were of good quality in all respects, the control stock(l-10) had a poor processability since-itcontained no styrene in theinterpolymer and exhibited a rubbery behavior on the roll, it wasdifficult to cut-back'the band and the roll sheet taken out of the rollhad a wrinkled surface. A stock containing 45% styrene (l-ll), onecontaining 50% of a-methylstyrene (l-9) and one not containingacrylonitrile (l-l2) in the interpolymer had not satisfactory headdistortion temperature, creep resistances, impact strengths,transparencies and tensile'strengths'because of poor compatibility ofthe interpolymer to vinyl chloride resin. Further, a stock containing25% of acrylonitrile in the interpolymer (1-13) Was'strongly discoloredto yellow and one of the a-methylstyrene content in the interpolymer of5% (l-8) had a low heat distortion temperature and a poor creepresistance.

Example 2 Various stocks were prepared varying the proportions of thethree components, of which physical properties were observed, in themanner as in Example 1. The re sults are indicated in the followingTable 3. I

As the interpolymer there was used the interpolymer sample B inExample 1. V

TABLE 3 Impact Heat Charpy V1nyl enhancdistor- Creep impact TensileDuromchloride Intiaring agfint t tion at 60 strength/ strength eterresln p yi en emp. awee Processa- (Kg-cm. Trans- K s hardness Ch Stock(101EP) mer, B B-202) 0.) (percent) bility sq. em.) parency Color m in?)D" l-esisiiii l 100 0 0 76 168 Fair 3.4 Excellent Colorless- 5.9 82Excellent.

95 0 3.6 Exeellent Colorless 6.1 83 95 5 14.5 d 5.8 82 i i 95 5 5. 9 82D0. 95 5 5. 7 80 D0. 95 5 40 5. 2 77 Good 00 10 0 2 90 10 10 2Z8 :5Eiggllent 90 10 20 6.1 32 Do 90 10 a0 5.3 81 D0: 90 10 40 5.1 78 Good 7030 0 6 2 70 30 10 6.2 :3 Eigguent' 70 30 20 6.0 83 Do: 70 30 30 5. 7 80Good 70 30 40 5. 1 78 Fair 50 50 0 109 48 Good 6.4 50 50 10 110Excellent 5. 2 Ghifii 50 50 20 10s 0 6.0 83 D0 50 50 30 107 Good 5.7 81D0 50 50 40 97 80 Fair 5. 2 78 Fair.

40 60 0 115 18 Good 6. 3 40 60 10 115 dO 6.4 l zii 40 60 20 113 18Excellent 6.2 82 D6 40 60 30 112 Good 6.0 81 Bad 2-26 40 60 40 104 69Fair 17.4 do do 5.7 79 Bad:

1 Not destrueted. NOTE .Starred are stocks of the present invention.

The chemical resistance was determined by observing the change in thesurface appearance during immersion of each stock at 60 C. for a week ineach of a 30% aqueous What is claimed is: 1. A vinyl chloride resincomposition having an excellent heat distortion property consistingessentially of a caustic soda, a 50% aqueous sulfuric acid, 40% aqueousmixture calcium chloride, methanol and glycerol. All of the stocks 1 fro of the present lnvention (starred) exhiblted good results. m 3 to 50%by Welght of a v1 nyl chlonde Among the control stocks (unstarred), onecontaining 40 resm an parts of the impact enhancing agent had poor heatdistor- 40 (2) 10% to 50% by Welght of an lntel'polymer tiontemperature, creep resistance, processability, tensile conslstlng ofstrength and hardness, one containing 60% of the inter- 5% to 40% byweight of styrene. polymer had a poor chemical resistance and one having5% to 20% by weight f acrylonitrile, an mterpolymer content of 5%exhlblted a slight rise of 30% to 80% Weight of methyl methacrylate,heat d1stort1on temperature. and Y 10% to 45% by weight ofa-methylstyrene. Example 3 2. The composltlon of claim 1 also mcluding1n ad- The results obtained by the tests in the similar manner mixturetherewith from 0 part to 30 parts by weight, per as in Examples 1 and 20n the Stock? Prepared using as 100 parts by weight of said mixture ofat least one imthe Impact finhanclng agent a Chlorlnated P y y pactstrength enhancing agent selected from the group (Elaslen 401 Sold ShowaDenko and chlom consisting of butadiene-containing polymers, chlorinatedsulfonated Polyethylene (hypal9n by polyethylene and chlorosulfonatedpolyethylene. Pont de Nemours and C0.) are Indicated 1n the followingTable 4. (References on following page) TABLE 4 Impact en- Charpy Vinylhancing Heat disimpact Tenslle chloride Interagent tortion Creep atstrength strength Durorneresin polymer, temp. 0.2 Proeessa- (Kg-0111.]Trans- (Kg./sq terhard- Chemical Stock (101EP) B (a) (b) (0) 0.) weekbility sq. em.) parency Color mm) ness D resistance 31* 30 10 102Excellent- 10.1 Excellent Colorless- 6.2 83 Excellent. 3-2* 70 30 20 10264 d0 21. 7 -..do do 6.0 83 D0. 3-3* 70 30 30 101 Good 5.7 Good. 34*-..70 30 40 105 5.1 73 Fair.

3-5* 70 30 10 104 Excellent- 9.5 Excellent C010 ess 6.2 83 Excellent.3-6* 70 30 20 103 51 ood 18.2 Good .do 6.1 82 Do. 3-

70 30 30 102 do 24.1 do .-.do 6.1 82 Do. 3-8.-.. 70 30 40 94 06 Bad 28.3Fair ..do. 6.0 81 Do.

39* 70 30 10 102 Good 8.3 Excellent. Sliglfltly 6.1 82 Excellent.

. e 0W. 3-10* 70 30 20 103 50 d0 16. 5 Good "Keen"- 6.2 81 Do. 3-11* 7030 30 102 .do d 6.0 81 Do. 3-12.-.. 70 30 40 95 98 Bad 6.0 81 Good.

1 Not destructed. N 0TE.Starred are stocks of the present invention.

(a) Hiblen B202, (13) Elaslen 401A, and (e) Hypelon 40.

References Cited UNITED STATES PATENTS Slocombe et a1 260898 Grabowskiet a1. 260-898 5 Salyer et a1. 260898 Jones et a1. 26080.78

10 FOREIGN PATENTS 571,254 2/1959 Canada.

SAMUEL H. BLECH, Primary Examiner M. J. TULLY, Assistant Examiner US.Cl. X.R.

